Generally, an undermount drawer slide rail assembly is mounted on the bottom of a drawer and is therefore hidden from view. An undermount drawer slide rail assembly typically includes a first rail and a second rail displaceable with respect to the first rail. More specifically, the first rail is mounted on the body of a cabinet, and the second rail is configured to carry or support a drawer so that the drawer can be easily pulled out of and pushed back into the cabinet body through the second rail with respect to the first rail. The undermount drawer slide rail assembly stays hidden at the bottom of the drawer even when the drawer is pulled out of the cabinet body.
As is well known in the art of furniture slide rails, a driving device can apply a driving force to a drawer (or slide rail) when the drawer (or slide rail) is in the last stage of a retracting process moving with respect to the body of a cabinet (or another slide rail) in a retracting direction from an opened position, wherein the driving force helps close the drawer with respect to the cabinet body. U.S. Pat. No. 5,207,781, for example, discloses a closing device for moving a drawer to a fully inserted position within a furniture body. As shown in FIG. 3 and FIG. 4 accompanying the specification of this U.S. patent, a tiltable member (3) is tilted into and thus locked in the arcuate portion (4″) of a guide track (4) when a drawer is moved in an opening direction with respect to a cabinet body. Consequently, a pin member (5) withdraws from a slot (9) of the tiltable member (3), allowing a spring (6) to store an elastic force. When the drawer is retracted with respect to the cabinet body, the pin member (5) reenters the slot (9) of the tiltable member (3) such that the tiltable member (3) returns to the rectilinear portion (4′) of the guide track (4), with the spring (6) pulling the tiltable member (3) and thereby retracting the drawer to a closed position with respect to the cabinet body. The disclosure of this US patent is incorporated herein by reference.